"The S.O. Has Only Got One Frond" is a popular drinking song in Headquarters, written by an unknown agent. While nobody remembers who wrote it or when, it's a common choice for disgruntled agents with strong beer and decent singing voices. "It [is] one of those songs that [has] the much-prized combination of catchiness, hardly ever being sung entirely sober, and being able to insult Upstairs without anyone minding overmuch."